Power supply system



Sept. 20, 1938. o. WOHLFARTH El AL 2,130,441

POWER SUPPLY SYSTEM Filed Aug. 16, 1955 IV/VVVVL INVENTOR s OTTOWOHLFARTH BY DE NIEM ATTORNEY Patented Sept. 20, 1938 2,130,441v

UNITED STATES PATENT OFFICE rowan SUPPLY SYSTEM Otto Wohlfarth andGiinther de Niem, Berlin, Germany, assignors to Allgemeine ElektricitatzGesellschaft, Berlin, Germany Application August 16, 1935, Serial No.36,507 In Germany August 25, 1934 6 Claims. (Cl. 25027) So-calledall-current amplifiers are known in that no special means need to beprovided with the prior art in which the filaments of the amplia view toeliminating the humming noises usualfier tubes and the filament of therectifier tube ly attendant upon mains-connected sets. The required forA. C. operation are connected in auxiliary tube in this instance couldbe employed series so that the tube may be heated directly also in A. C.operation in which instance it offers 5 or else by way of a seriesresistance from the supthe advantage that the means customarily replynetwork regardless of what system or kind of quired for smoothing theplate potential may be current is concerned. Inasmuch as suchall-curdispensed with. rent receivers are connected without a network Afundamental key diagram is shown in the transformer, there results aplate potential which drawing. The terminals 1 and 2 serve at will for lin D. C. operation may be substantially below connection with 110 or 220v. D. C. voltage or the line or network voltage, and in A. C.operaalternating voltage mains. The circuit is, of tion at the mostequal to the line potential. In course, suited also for other, abnormal,line volt- A. C. operation the voltage is therefore slightages. In theinstance here shown two switches 3 16 ly higher than in D. C. workingseeing that and 4, according to the line supply voltage and owing to theuse of large condensers after rectithe kind of current must bepositioned as folfication a D. C. voltage higher than the effectivelows: voltage may be obtained. The plate potentials Positionafor 110volts D.C.

obtainable with such universal receivers are not b for 220 volts D. C.

20 sufiicient for present day power or end-stage cfor 220 volts A. C. 20

tubes since these tubes whenever a high undisdfor 110 volts A. C. tortedoutput power is required, require a plate The main transformer isdenoted by 5 in the voltage between 250 and 350 v. drawing. Thistransformer, contradistinct to the Amplifiers of this kind arepractically useless usual mains connected transformers, may be in thecase of 110-v. supply-lines because the made considerably smaller insize inasmuch as 25 plate voltage of the power tube is lower than thatit is calledupon the furnish only the low plate of a standard batteryoperated set. energies for the amplifier tubes. The ends of the Now, thepresent invention is predicated upon secondary winding of the maintransformer, in the idea that in an all-current amplifier the thecustomary way, are brought through a rectiplate voltage for theamplifier tube must be fier tube 6 and smoothing means 1 to the ampli-30 equally satisfactory and adapted in any case refier or receiver showngenerally at 8 properly sogardless of system of current and of voltage.called. The negative terminal of the output side Hence, in the case ofthe plate potential supply, of the smoothing means I is connected toground in A. C. operation, a network or mains transthrough a by-passcondenser l3. The filaments former must be used which produces therequisite of all of the tubes, as in the exemplified embodi- 35alternating voltage and which, in the usual way, ments, are in seriesdirectly with the line-supply is adaptable by re-connection or change ofcirpotential. According to the value of this voltage cuit to operationon either 110 or 220 v. For D. C. will a series resistance 9 be eithershort-circuit operation. according to the invention, an auxilor be cutin circuit.

iary tube is used whose filament is connected to- Now, in order thatwith the use of the all-cur- 40 gether with the mains transformer.Primary and rent or amplifier if D. C. is employed, the desecondarywindings of the transformer are so sired alternating voltage may beavailable upon connected at the grid and the plate of the auxilthesecondary end of the main transformer, the iary tube that the tubeoperates as a transmitter. scillatory circuit (auxiliary transmitter)with The plate voltage of the auxiliary tube consists the auxiliaryoscillator tube I8 is used according 45 of the D. C. of the network. Thewinding of the to the invention. The oscillation circuit itself mainstransformer united with the rectifier tube is essentially composed ofthe primary coil of and which at the same time is arranged as an thetransformer 5 and a condenser H whose size autotype transformer raisesthe alternating voltis governed by the frequency of the said auxiliary 5age produced by the transmitter to the requisite transmitter tube. Thetube I0 is of the three magnitude. The frequency generated by theelement type having an anode, a cathode, and a auxiliary transmitter maybe chosen at will, but control electrode. The anode-to-cathode circuitit may fall inside the tonal frequency range. is through the primary oftransformer 5, while The arrangement could also be chosen in such a thegrid-to-cathode is through a portion of the way that a supersonicfrequency is produced so secondary of transformer 5, it being noted thata 55 connection is provided including a condenser l5 between the grid oftube Ill and a point of the secondary of the transformer 5. The grid isalso connected to the cathode through a resistor it. As previouslypointed out, the available source of voltage is connected across theterminals 5 and 2 so that in the event that D. C. operation is desired,the terminals l and 2 are connected to the D. C. source so that terminal2 is maintained at a positive potential with respect to terminal l. Thefilament heating circuit for the tubes is grounded through a by-passcondenser 52 as shown.

In operation it will be evident that while the switches 3 and 4 are inthe positions denoted by c and cl in the drawing the auxiliary tube ii)is short-circuited. Its filament under these conditions may also beshort circuited by means of the plug it. When switches 3 and t, are inpositions a and b the auxiliary tube ill will be conditioned so as togenerate an alternating voltage in the transformer. The resistance 9 ispreferably so dimensioned that the same voltage will be available acrossterminals I and Il irrespective of whether the applied voltage is or 220volts A. C. or D. C.

Arrangements could also be chosen in such a way" that the auxiliary tubestays in circuit also in case of A. C. opeation. The frequency to bechosen for the auxiliary oscillator or transmitter should be suitable sothat it will be supersonic, for this would require less extensivesmoothing means.

We claim:

1. In an amplifier system a plurality of thermionic tubes includingindirectly heated and anodes, said cathodes being provided with heatermeans, a rectifier provided with an indirectly heated cathode and ananode, heater means for the last named cathode, a circuit including aresistor device and all of the heater means in series, said circuitbeing adapted to be connected to either a source of direct currentenergy or a source of alternating current energy to thereby energize allof the heater means, an auxiliary circuit including a transformer forconnecting the recti er to the source of alternating current to therebyrectify energy from the source, a filter connected to the output of saidrectifier, connections from the filter to the anodes of the thermionictubes, a vacuum tube oscillator adapted to be connected through suitableswitching means to a source of direct current energy so as to beenergized thereby, means for connecting the vacuum tube oscillator tothe rectifier whereby the output of the oscillator is rectified andselective switching means for connecting the oscillator to the rectifierthrough said transformer when in one position and the source ofalternating current to the rectifier through said transformer when inanoth r position.

2. An arrangement as described in claim further characterized by thatmeans are provided for adapting the systems for use at differentavailable voltage 3. An arrangement as described in claim 1.characterized by that the transformer is used as a mains transformer inthe case where alternating voltages are employed and as the feed backmeans for the vacuum tube oscillator when D. C. voltage is employed.

5. In a relay circuit, a plurality of thermionic tubes each of which isprovided with an indirectly heated cathode and an anode, powerconditioning circui for said tubes including a pair of input terminalsfor connection of the conditioning circuit to either a direct currentcommercial network or to an alternating current commercial network, apower transfomer, switching means for selectively connecting anddisconnecting the .ary of the transformer across said input terminals, arectifier tube having an anode and an indirectly heated cathode, meansfor connecting the anode of the rectifier tube to one end of thesecondary of the power transformer, means for connecting the cathode ofthe rectifier tube to the anodes of the first named thermionic tubes,said means including a choke coil, means for connecting the cathodes ofsaid first named thermionic tubes to the other end of the secondarywinding, said last named connection being grounded through a condenser,an oscillator tube including an anode, a cathode and a controlelectrode, means for connecting the anode to one end of the ,ima2'ywinding of said transformer, the other old of primary winding beinggrounded through a condenser element, means connecti g the cathode o theoscillator tube to the input terminal corresponding to the end of theprimary winding to which the last named anode is connected, meansincluding a condenser for corn necting the control electrode of saidoscillator tube to point of the secondary of said transformer, cathodeenergizin circuit [or the oscillator tube and a grid leak meansconnected between the control electrode and cathode of the oscillatortube.

5. In a relay circuit, a plurality of thermionic tubes, each thereofbeing provided with an indirectly heated cathode and an anode, a powerconditioning circuit for energizing the tube ele ments including a pairof input terminals for connection of the conditioning circuit to eithera direct current commercial network or to an alternating currentcommercial network, a power transformer, switching means for selectivelyconnesting and disconnecting the primary of the transformer across saidinput terminals, a rectifier tube having an anode and an indirectlyheated cathode, means for connecting the anode of the rectifier tu e toone end of the secondary of the power transformer, means for connectingthe cathode of the rectifier tube, and including choking device forconnecting the cathode of the rectifier tube to the anodes of the firstnamed thermionic tubes, a filter condenser connected between the anodecathode of the rectifier tube, heater elements for the cathode of therectifier tube and the cathodes of said thermionic tubes, said heaterelements being connected in seties across said input terminals wherebythe heater elements are energized upon connection of the input terminalsto either a direct current network or alternating current network, anoscillator tube having an anode, a cathode and a control electrode,external circuits including the power transformer for forming input andoutput circuits for the oscillator tube, said powe transformer acting tocouple the output circuit to the input circuit thereby facilitate thetransfer of energy from the output circuit of the oscillator tube to theinput circuit thereof for producing oscillation said switching meansbeing arrange to connect said oscillator tube across the input terminalswhen the primary of the tube transformer is disconnected by theswitching means and to short ciJ. t the oscillator tube when the mary ofthe transformer is connected across the input terminals by operation ofthe switching means.

6. In a power conditioning circuit for energizing the tube elements ofelectronic relays, a thermionic oscillator tube including an anode, acathode and a control electrode, a pair of terminals for connection to adirect current network or an alternating current network, one of saidterminals being a positive terminal and the other thereof a negativeterminal in direct current network operation, a transformer having aprimary winding and a secondary winding, an anode to cathode circuit forsaid tube including the primary winding of said transformer, a controlelectrode to cathode circuit for said tube including a capacity and atleast a portion of the secondary of said transformer, said transformerbeing arranged so as to facilitate the transfer of energy from the anodeto cathode circuit to the control electrode to cathode circuit forgenerating oscillations, a cathode energizing circuit for said tubeconnected between the positive and negative terminals, a rectifier tube,said tube including an anode and a cathode, a positive output terminaland a negative output terminal for said rectifier tube, and adapted tohave a load circuit connected thereto, means for connecting the cathodeof the rectifier tube to the positive output terminal, said meansincluding a choke, means including the secondary of said transformer forconnecting the anode of the rectifier tube to the negative outputterminal, a filter condenser connected across the anode and cathode ofthe rectifier tube, and means for adapting said power conditioningcircuit for connection across an alternating current network comprisingcircuit means for connecting the primary of said transformer directlyacross said first named pair of terminals.

OTTO WOHLFARTH. GfiNTHER DE NIEM.

